Psychological manipulation is a type of social influence that aims to change the perception or behavior of others through underhanded, deceptive, or even abusive tactics.[1] By advancing only the interests of the manipulator, often at the other's expense, such methods could be considered exploitative, abusive, devious, and deceptive.

Social influence is not necessarily negative. For example, doctors try to persuade patients to change unhealthy habits. [citation needed] Social influence is harmless when it respects the right of the influenced to accept or reject it, and is not unduly coercive. Depending on the context and motivations, social influence may constitute underhanded manipulation.

intermittent or partial reinforcement - Partial or intermittent negative reinforcement can create an effective climate of fear and doubt, for example in terrorist attacks. Partial or intermittent positive reinforcement can encourage the victim to persist - for example in most forms of gambling, the gambler is likely to win now and again but still lose money overall.

traumatic one-trial learning - using verbal abuse, explosive anger, or other intimidating behavior to establish dominance or superiority; even one incident of such behavior can condition or train victims to avoid upsetting, confronting or contradicting the manipulator.

Lying: It is hard to tell if somebody is lying at the time they do it although often the truth may be apparent later when it is too late. One way to minimize the chances of being lied to is to understand that some personality types (particularly psychopaths) are experts at the art of lying and cheating, doing it frequently, and often in subtle ways.

Lying by omission: This is a very subtle form of lying by withholding a significant amount of the truth. This technique is also used in propaganda.

Denial: Manipulator refuses to admit that he or she has done something wrong.

Rationalisation: An excuse made by the manipulator for inappropriate behavior. Rationalization is closely related to spin.

Minimization: This is a type of denial coupled with rationalization. The manipulator asserts that his or her behavior is not as harmful or irresponsible as someone else was suggesting, for example saying that a taunt or insult was only a joke.

Selective inattention or selective attention: Manipulator refuses to pay attention to anything that may distract from his or her agenda, saying things like "I don't want to hear it".

Diversion: Manipulator not giving a straight answer to a straight question and instead being diversionary, steering the conversation onto another topic.

Guilt tripping: A special kind of intimidation tactic. A manipulator suggests to the conscientious victim that he or she does not care enough, is too selfish or has it easy. This usually results in the victim feeling bad, keeping them in a self-doubting, anxious and submissive position.

Shaming: Manipulator uses sarcasm and put-downs to increase fear and self-doubt in the victim. Manipulators use this tactic to make others feel unworthy and therefore defer to them. Shaming tactics can be very subtle such as a fierce look or glance, unpleasant tone of voice, rhetorical comments, subtle sarcasm. Manipulators can make one feel ashamed for even daring to challenge them. It is an effective way to foster a sense of inadequacy in the victim.

Playing the victim role ("poor me"): Manipulator portrays him- or herself as a victim of circumstance or of someone else's behavior in order to gain pity, sympathy or evoke compassion and thereby get something from another. Caring and conscientious people cannot stand to see anyone suffering and the manipulator often finds it easy to play on sympathy to get cooperation.

Vilifying the victim: More than any other, this tactic is a powerful means of putting the victim on the defensive while simultaneously masking the aggressive intent of the manipulator.

Playing the servant role: Cloaking a self-serving agenda in guise of a service to a more noble cause, for example saying he is acting in a certain way for "obedience" and "service" to God or a similar authority figure.

Feigning innocence: Manipulator tries to suggest that any harm done was unintentional or did not do something that they were accused of. Manipulator may put on a look of surprise or indignation. This tactic makes the victim question his or her own judgment and possibly his own sanity.

Feigning confusion: Manipulator tries to play dumb by pretending he or she does not know what you are talking about or is confused about an important issue brought to his attention.

Brandishing anger: Manipulator uses anger to brandish sufficient emotional intensity and rage to shock the victim into submission. The manipulator is not actually angry, he or she just puts on an act. He just wants what he wants and gets "angry" when denied.

over-intellectualization - victim tries too hard to understand and believes that manipulator has some legitimate understandable reason to be hurtful.

emotional dependency - victim has a submissive or dependent personality. The more emotionally dependent the victim is, the more vulnerable he is to being exploited and manipulated.

Manipulators generally take the time to scope out the characteristics and vulnerabilities of their victim.

According to Kantor[3], the following are vulnerable to psychopathic manipulators:

too trusting - people who are honest often assume that everyone else is honest. They commit themselves to people they hardly know without checking credentials etc. They rarely question so-called experts.

too dependent - dependent people need to be loved and are therefore gullible and liable to say yes to something they should say no to.

too lonely - lonely people may accept any offer of human contact. A psychopathic stranger may offer human companionship for a price.

too impulsive - make snap decisions about, for example, what to buy or who to marry without consulting others.

too frugal - cannot say no to a bargain even if they know the reason why it is so cheap

being elderly - the elderly can become fatigued and less capable of multi-tasking. When hearing a sales pitch they are less likely to consider that it could be a con. They are prone to giving money to someone with a hard-luck story. See elder abuse.

Some psychopaths are opportunistic, aggressive predators who will take advantage of almost anyone they meet, while others are more patient, waiting for the perfect, innocent victim to cross their path. In each case, the psychopath is constantly sizing up the potential usefulness of an individual as a source of money, power, sex or influence. Some psychopaths enjoy a challenge while others prey on people who are vulnerable. During the assessment phase, the psychopath is able to determine a potential victim’s weak points and will use those weak points to seduce.

Once the psychopath has identified a victim, the manipulation phase begins. During the manipulation phase, a psychopath may create a persona or mask, specifically designed to ‘work’ for his or her target. A psychopath will lie to gain the trust of their victim. A psychopath’s lack of empathy and guilt allows them to lie with ease - they don’t see the value of telling the truth unless it will help get them what they want.

As interaction with the victim proceeds, the psychopath carefully assesses the victim's persona. The victim's persona gives the psychopath a picture of the traits and characteristics valued in the victim. The victim's persona may also reveal, to an astute observer, insecurities or weaknesses the victim wishes to minimize or hide from view. As an ardent student of human behavior, the psychopath will then gently test the inner strengths and needs that are part of the victim's private self and eventually build a personal relationship with the victim.

The persona of the psychopath - the “personality” the victim is bonding with - does not really exist. It was built on lies, carefully woven together to entrap the victim. It is a mask, one of many, custom-made by the psychopath to fit the victim's particular psychological needs and expectations. The victimization is predatory in nature; it often leads to severe financial, physical or emotional harm for the individual. Healthy, real relationships are built on mutual respect and trust; they are based on sharing honest thoughts and feelings. The mistaken belief that the psychopathic bond has any of these characteristics is the reason it is so successful.

The abandonment phase begins when the psychopath decides that their victim is no longer useful. They abandon their victim and move on to someone else. In the case of romantic relationships, a psychopath will usually seal a relationship with their next target before abandoning their current victim. Abandonment can happen quickly and can occur without the current victim knowing that the psychopath was looking for someone new. There will be no apologies for the hurt and pain they cause because psychopaths do not appreciate these emotions.